Book Joel M, Asokanthan Samuel F
Department of Mechanical and Materials Engineering, The University of Western Ontario, 1151 Richmond Street, London N6A 5B9, Canada.
Insects. 2012 Oct 22;3(4):1028-38. doi: 10.3390/insects3041028.
Previous dynamic characterizations of the cercal mechanosensory hairs of crickets have generally been limited to the first resonant frequency and associated deflection shape. A more complete description of the mechanical dynamics of these structures could be obtained by an experimental modal analysis. This paper describes a method by which a full experimental modal analysis, giving natural frequency, mode shape, and modal damping ratio, of these sense organs can be performed. Results of this analysis, employing an unmeasured moving-air excitation and non-contact vibration measurement with an output-only identification method are presented. Two distinct types of behaviour were observed, one of which was a good match for the behaviour expected based on the literature, and one of which was quite different. These two behaviours had distinct patterns of modal parameters. The method described in this paper has been shown to be able to estimate the modal parameters, including natural frequency, modal damping ratio, and normalized mode shape, for the first mode of cercal mechanosensory hairs of crickets. The method could practically be extended to higher modes and a wide variety of other sound and vibration sense organs with the selection of appropriate excitation and specimen supports.
此前对蟋蟀尾须机械感觉毛的动力学特性描述通常仅限于第一共振频率及相关的偏转形状。通过实验模态分析可以更完整地描述这些结构的机械动力学特性。本文描述了一种方法，通过该方法可以对这些感觉器官进行全面的实验模态分析，得出固有频率、振型和模态阻尼比。文中给出了采用未测量的动气激励和非接触式振动测量以及仅输出识别方法的该分析结果。观察到两种不同类型的行为，其中一种与基于文献预期的行为非常匹配，另一种则大不相同。这两种行为具有不同的模态参数模式。本文所述方法已被证明能够估计蟋蟀尾须机械感觉毛第一模态的模态参数，包括固有频率、模态阻尼比和归一化振型。通过选择合适的激励和标本支撑，该方法实际上可以扩展到更高阶模态以及各种各样的其他声音和振动感觉器官。
